Animation problems

steveO · 27 Mar 2013, 13:11

Hey guys a have a fairly large model i wish to make an animation with (just a hobby). problem is i get bad clipping. (i assume thats what it is called) where a large part of the model is cut away when you zoom close enough. Also the final animation size is way to big, over 3 gig when i set the animation size to 640x480 with 24 fps and 18 scenes. which appart from this clipping problem, no media player i have- vlc,windows media plyr,real plry and others can play it.. i hav no problems with animation of smaller models but this is a large model. both file size and scale. Any sugestions to fix these problems will be appreciated

pilou · 27 Mar 2013, 14:30

Search the more large view and make a Zoom extends on it then remake your animation?

Jean Lemire · 27 Mar 2013, 15:26

Hi Steve, hi folks.

Are you using parallel projection or perspective? Parallel projection is more prone to clipping.

Also, is your model close to the axes origin? Models that are far away from this origin are more prone to experience clipping.

Also, is your model very huge? Huge model are more prone to experience clipping. Even a small model can be huge if there is a small stray geometry far away from it. For example, even a small house can be seen as a huge model if there is even a single edge many kilometers away. If you happen to align this edge, the house and the camera position, you are asking for trouble.

To diagnose that, select all and create a group with the selection. Select the group. If the selection box seems to enclose only the model, you are OK. If the box seems unusually huge, you have a problem. Explode the newly created group since its purpose is only to help in diagnostic. However, if you prefer, you may keep it and double click it to enter its context and do the following procedure:

1 - Zoom, orbit and pan to see all of the model that you want.

2 - Select all. All the model will be selected, including any stray geometry.

3 - Press and hold down the SHIFT key to Add/Subtract from the selection.

4 - While still holding the SHIFT key, select the model with a selection window, for example. This deselect it and only the stray geometry remains selected.

5 - Delete the selection.

A possible shorcomming is that if the stray geometry is aligned behind the model it will be deselected as well and the problem is not solved. If this is the case, orbit at least 90° to position this geometry to one side or the other and then redo the above procedure.

If you kept the group made with the model and any stray geometry, you shall see the bounding box srinks after deleting the selection in step 5 above. If this is the case, you have probably solved this part of the problem and you can now explode that group.

Just ideas.

steveO · 28 Mar 2013, 04:52

thanks for the reply's, i did post a reply earlier but it doesn't seem to have go through. yes its a very large model. its a very detailed star destroyer from starwars i have been building, so its over 1.1km long with interior and hangers. i want the animation to be able to zoom right up to the bridge and in the hangers, where some objects are as small as 200mm.

also the model starts at the axes origin point.
i have created animations in the past which work but i wanted background models in this animation which make the work space allot larger, which is what i believe is causing the problem.. is there a way to solve this without having to compromise and have nothing in the background?

Is what i want to do possible using sketchup animation?

Jean Lemire · 28 Mar 2013, 18:41

Hi Steve, hi folks.

Maybe you can try using an image as a background.

Have you envisonned something like a Watermark?

However, this watermark image will remain still when orbitting so it may look unnatural.

Another possibility is to have an image applied to a spherical face behind the model. Try using the smallest sphere possible. As per your description of a 1.1 km spaceship, it means that it has a half length of 550 m. MAybe a sphere with a radius of 600 or 700 m will do.

I tried something with a radius of 1 km. See this SU file where I put a sphere with a radius of 550 m inside one with a radius of 1000 m. I also put an octaedron of 200 mm at their center. I can zoom in but there is a limit. I will let you experience with it.

Huge model of spaceship.skp
I also tested this concept with a smaller outer sphere with a radius of 750 m but the difference was negligible (I could not really zoom in much closer).

I think that this is a limitation of OpenGL where the relative size of 2 objects overshoot some threshold value.

What is possible is that you make your animation in parts.

Part 1 would be done with the full model (spaceship and external surroundings) and would include the external approach and the entry inside the spaceship.

Part 2 would be done with a subset of the model (only the spaceship without any surroundings) and would include the walkthrough inside the spaceship.

Part 3 would be done with a smaller subset of the model (only the relevant parts of the spaceship) and would include the walk inside the relevant rooms. Being smaller, it would allow zooming in more on details as small as you would like.

Just ideas.

steveO · 29 Mar 2013, 06:35

Thanks for your reply's again.. i had not thort of breaking it up.. i did solve the problem of massive size of final animation by exporting the animation as a png. rather than an avi and then used ImagesToVideo to combine to make the vid. (i did this with another model) but i tried exporting in both ways- 1 way was the avi and the other in png the avi file was 1.2 gig while the png that once converted was only 60 mb.. also the png exporting was alot faster.

I will defiantly look at breaking up the animation into parts and try it that way and also look at the sphere background around the model